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Matt, Mechanical Engineer

Category: Car

Satisfied Customers: 22736

Experience: BEng hons Mech engineering, in auto industry 22 years

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I have a 55 plate zafira 1.6 petrol manual car. I

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Hi, i have a 55 plate zafira b 1.6 petrol manual car. I recently started experiencing starting problems where car would turn and start when cold but not turn when hot. I assumed that the starter was playing up ie jamming when hot. I checked my battery and that returned over 12.6v, I changed the starter motor but no good. The dash lights come on but there is no click of the starter solenoid. I can start the car with a push start. I checked the starter conections and i have 12.7v at the starter live, the starter casing is earthed. I then checked if i had a voltage on the switch connection of the starter when the key was turned- no voltage. I then checked the 25amp fuse in the box this is ok. A continuity check proved the starter wire back to the connector block outside the fuse box. I have continuity between the external connector block and a pin connector for the fuse. When turning the key i hear a relay clicking so assume that the key barrel is ok. There is no voltage pushing current down to the starter. I can only assume i have an issue between the relay and the external connector block? I have changed the battery in the keyfob as a precaution since it has not been done for years. So would apreciate help, i am available to ans questions

HelloOK there's a few things to check here1st check that the main battery cables are on tight and the terminals are clean and bright. Do the same for the engine / gearbox earth strap.Then follow the main positive lead back to the engine and down to the starter motor, and check the connection at this end as well. There should also be a small wire to the motor which should have 12V when you're turning the ignition switch to crank. If the 12V isn't there, check back along this wire for damage to the insulation or corroded connections This 12V feed comes directly from the ignition switch so this may be faulty and need replacing Check the resistance of the main positive lead that runs down to the motor as anything more than a few ohms and it should be replacedDon't forget to try a jump start from another car / battery as its possible the battery is poor, if you have a voltmeter a healthy battery should read 12.7+V also try substituting the battery for another as I've known a very flat battery to drag down the system voltage too far even with jump cablesone other thing to consider is that the immobiliser is faulty and preventing the starter from being enabled - however if the dash / ignition lights are on then this usually means that its off

Hi many thanks for your time and reply, everything u have suggested i had listed in my question, battery giving nearly 13v, getting voltage at stater live but none for the solenoid switch, battery connections ok, swich cable continuos and v low resistance etc etc relay clicking key switch ok, fuse ok etc etc i can not get a current to flow to the starter switch, lights on dash on imob ok, will push start will not crank off jump leads.... I have looked at circuit diagrams and physically traced wires etc so fairly confident of set up. Pls re read my orig question and your thoughts are welcome. Only thing i have not checked is earth strap to body, have to find this? Unless i can point it out. Many thanks

Customer:replied 2 years ago.

Hi

im getting a kittle bit exasperated with this. I have gone through various checks again also i have followed your suggestions all not successful.

checks done:

1 rechecked both starters on the bench with 12v battery, bot working ok

2 checked continuity and resistance on power line from battery to starter live, 12.7v, continuitybok, low ohms.

OK one other thing to check / try is for hot climates there should be a heat shield between the starter motor and the engine, so it may be worth adding something to prevent radiated heat from the engine block / exhaust getting to the motor

Thanks for taking the time to reply, I listed the logical sequence of checks i have done investigating my starting issues, i am working on the basis i have an electrical problem, i expected an expert to review what i have done, critique it or suggest the next step ie check/ replace fuse box or something else..... I am not sure replacing or increasing heat shielding is a logical next step in elliminating electrical or electronic faults that may or may not be the cause especially when i can not start the car and generate any heat. Pls review the checks i have done and in your vast experience and expertise suggest what could be casuing my problem given the checks i have doneThanks

Hi, i have checked the main earth as listed prev this was in good condition continuos and low ohms, i will look for the earth from the fuse box to the chassis and check this, i have the same feeling it is a power issue. Thanks i will be happy to pay for advice and pay extra when it leads to a succesful end what would make me unhappy would be payin out money but not resolving the issue.

Thanks, , my next port of call is to start tracing the wiring As u suggested and checking continuity and resistance etc I am also going to recheck key 12v live to relay just in case there a fault here and to make sure i have 12 v back from key connectionWill keep u postedAzeem

just to let u know, i was not able to sort the problem and had to call in a mobile auto tech. He spent around an hour and 45mins working through various things. Initially his diagnostic dubry showed a mass of error messages and fault codes, prob from all my messing around, he managed to get rid of most, eventually found a comuncation problem between the management system and the ignition system, he sorted this then cleared a few other faults for me. Car running and ok at moment.

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